Asphaltum Laquer Bitumen, black, in turpentine, with colophony.
Appearance: Undercoating: Immediately after application of the tempera or oil-based paint, the asphalt paint underneath starts to grow through strongly. The tempera paint is most affected and turns greenish to brownish within a few hours. At the same time, pronounced early shrinkage cracks form in the tempera paint layer and wrinkles form in the oil paint layer.
Final glaze: High gloss, varnish-like smooth, homogeneous, well flowing color with intensive, warm tinting on the oil layer. On the tempera color layer, the color is noticeably duller and colder from the start.
Drying/Curing: Underpainting: delayed drying of the tempera or oil paint due to the asphalt underpainting growing through. The panels retain their discoloration even after drying is complete.
Final glaze: The paint sets very quickly and hardens the fastest of all 10 paints. On the tempera undercoats, it sometimes sinks heavily and completely loses its peculiar, varnish-like character.
Aging: Primary yellowing is not noticeable with the asphalt finishing glazes, since no oil is present. Very strong fading of the asphalt final glazes on all panels, especially on the tempera substrates.
